Most positive HIV western blot tests do not diagnose new cases in New York City: implications for HIV testing programs

"I wanted evidence that my status had changed, so that is why I tested": experiences with HIV self-testing among female sex workers in Malawi

HIV testing among female sex workers (FSWs) is an established global health priority. HIV self-testing (HIVST) seems to have the potential to address issues of confidentiality, privacy and convenience among this key population. HIVST, however, may result in unintended consequences as its implementation unfolds in a complex sex work context characterised by unequal power relations, stigma and high HIV prevalence. We aimed to explore the experiences of FSWs with HIVST in the context of retesting and antiretroviral usage in Blantyre, Malawi. We used an ethnographic approach to understand meanings and views around HIVST and retesting. We found high levels of retesting, especially among those on antiretroviral, two of which received "false-negative" results. We identified three broad narratives: (1) retesting in response to experiences in the sex work context, (2) retesting driven by the desire to self-monitor HIV-negative status, and (3) retesting in the hope of sero-reversion. The FSWs' experiences indicate that the implementation of HIVST in this context is complex with potential for unintended harms such as coercive testing. HIVST programmes must include clear and appropriate messaging to reduce retesting while on ART and implement strategies to address FSW concerns and anxieties about the accuracy of their HIV-positive test results.

Estimating the costs and cost-effectiveness of HIV self-testing among men who have sex with men, United States

INTRODUCTION

HIV testing is an essential prerequisite for accessing treatment with antiretroviral therapy or prevention using pre-exposure prophylaxis. Internet distribution of HIV self-tests is a novel approach, and data on the programmatic cost of this approach are limited. We analyse the costs and cost-effectiveness of a self-testing programme.

METHODS

Men who have sex with men (MSM) reporting unknown or negative HIV status were enrolled from March to August 2015 into a 12-month trial of HIV self-testing in the United States. Participants were randomly assigned either to the self-testing arm or the control arm. All participants received information on HIV testing services and locations in their community. Self-testing participants received up to four self-tests each quarter, which they could use themselves or distribute to their social network associates. Quarterly follow-up surveys collected testing outcomes, including number of tests used and new HIV diagnoses. Using trial expenditure data, we estimated the cost of implementing a self-testing programme. Primary outcomes of this analysis included total programme implementation costs, cost per self-test completed, cost per person tested, cost per new HIV diagnosis among those self-tested and cost per quality adjusted life year (QALY) saved.

RESULTS

A total of 2665 men were assigned either to the self-testing arm (n = 1325) or the control arm (n = 1340). HIV testing was reported by 971 self-testing participants who completed a total of 5368 tests. In the control arm, 619 participants completed 1463 HIV tests. The self-testing participants additionally distributed 2864 self-tests to 2152 social network associates. Testing during the trial identified 59 participants and social network associates with newly diagnosed HIV infection in the self-testing arm; 11 control participants were newly diagnosed with HIV. The implementation cost of the HIV self-testing programme was $449,510. The cost per self-test completed, cost per person tested at least once, and incremental cost per new HIV diagnosis was $61, $145 and $9365 respectively. We estimated that self-testing programme potentially averted 3.34 transmissions, saved 14.86 QALYs and nearly $1.6 million lifetime HIV treatment costs.

CONCLUSIONS

The HIV self-testing programme identified persons with newly diagnosed HIV infection at low cost, and the programme is cost saving.

Monitoring progress towards the first UNAIDS target: understanding the impact of people living with HIV who re-test during HIV-testing campaigns in rural Mozambique

INTRODUCTION

Awareness of HIV-infection goes beyond diagnosis, and encompasses understanding, acceptance, disclosure and initiation of the HIV-care. We aimed to characterize the HIV-positive population that underwent repeat HIV-testing without disclosing their serostatus and the impact on estimates of the first UNAIDS 90 target.

METHODS

This analysis was nested in a prospective cohort established in southern Mozambique which conducted three HIV-testing modalities: voluntary counselling and testing (VCT), provider-initiated counselling and testing (PICT) and home-based testing (HBT). Participants were given the opportunity to self-report their status to lay counsellors and HIV-positive diagnoses were verified for previous enrolment in care. This study included 1955 individuals diagnosed with HIV through VCT/PICT and 11,746 participants of a HBT campaign. Those who did not report their serostatus prior to testing, and were found to have a previous HIV-diagnosis, were defined as non-disclosures. Venue-stratified descriptive analyses were performed and factors associated with non-disclosure were estimated through log-binomial regression.

RESULTS

In the first round of 2500 adults randomized for HBT, 1725 were eligible for testing and 18.7% self-reported their HIV-positivity. Of those tested with a positive result, 38.9% were found to be non-disclosures. Similar prevalence of non-disclosures was found in clinical-testing modalities, 29.4% (95% CI 26.7 to 32.3) for PICT strategy and 13.0% (95% CI 10.9 to 15.3) for VCT. Prior history of missed visits (adjusted prevalence ratio (APR) 4.2, 95% CI 2.6 to 6.8), younger age (APR 2.5, 95% CI 1.4 to 4.4) and no prior history of treatment ((APR) 1.4, 95% CI 1.0 to 2.1) were significantly associated with non-disclosure as compared to patients who self-reported. When considering non-disclosures as people living with HIV (PLWHIV) aware of their HIV-status, the proportion of PLWHIV aware increased from 78.3% (95% CI 74.2 to 81.6) to 86.8% (95% CI 83.4 to 89.6).

CONCLUSION

More than one-third of individuals testing HIV-positive did not disclose their previous positive HIV-diagnosis to counsellors. This proportion varied according to testing modality and age. In the absence of an efficient and non-anonymous tracking system for HIV-testers, repeat testing of non-disclosures leads to wasted resources and may distort programmatic indicators. Developing interventions that ensure appropriate psychosocial support are needed to encourage this population to disclose their status and optimize scarce resources.

Multiple strategies to identify HIV-positive black men who have sex with men and transgender women in New York City: a cross-sectional analysis of recruitment results

INTRODUCTION

Black men who have sex with men and transgender women are at high risk for HIV infection, but are more likely to be unaware of their infection or not in care for diagnosed HIV compared to other races. Respondent driven sampling has been advanced as a method to reach stigmatized and hidden populations for HIV testing. We compared strategies to recruit black, substance-using men who have sex with men and transgender women to identify newly diagnosed HIV infection, or those previously diagnosed but not in care.

METHODS

The STAR (Seek, Test, and Retain) study (ClinicalTrials.gov NCT01790360) used several recruitment strategies to identify black, substance-using men who have sex with men and transgender women with undiagnosed HIV infection or with previously diagnosed HIV infection but who were not in HIV care. Respondent-driven sampling, community-based recruitment and online advertising were used to recruit participants. Incentivized peer referral was integrated into all recruitment strategies. Participants completed interviewer-administered questionnaires and HIV testing. Demographic and HIV risk-related characteristics and recruitment strategy were summarized and stratified by HIV status. Associations were tested using Pearson's chi-squared, Fisher's exact, and Wilcoxon rank sum tests. Factors associated with HIV-positive diagnosis at p < 0.1 were included in a multivariable logistic regression model.

RESULTS

From July 2012 through October 2015, the study enrolled 1929 participants; 96.3% men who have sex with men and 3.7% transgender women. Behavioural risk factors included recent condomless anal sex (55.6%) and recent substance use during sex (73.1%). HIV prevalence was 8.7%. In multivariable analysis, significant associations with HIV infection included being transgender; non-Hispanic black; gay/homosexual orientation; not homeless; and less likely to have insufficient income for necessities. Among recruitment strategies, respondent driven sampling was least effective in identifying HIV-positive participants.

CONCLUSIONS

Integrating multiple recruitment strategies yielded a large sample of black men who have sex with men and transgender women at substantial risk for HIV. Respondent-driven sampling was less effective than other strategies at identifying men who have sex with men and transgender women with HIV.

An Adaptive Approach to Locating Mobile HIV Testing Services

BACKGROUND

Public health agencies suggest targeting "hotspots" to identify individuals with undetected HIV infection. However, definitions of hotspots vary. Little is known about how best to target mobile HIV testing resources.

METHODS

We conducted a computer-based tournament to compare the yield of 4 algorithms for mobile HIV testing. Over 180 rounds of play, the algorithms selected 1 of 3 hypothetical zones, each with unknown prevalence of undiagnosed HIV, in which to conduct a fixed number of HIV tests. The algorithms were: 1) Thompson Sampling, an adaptive Bayesian search strategy; 2) Explore-then-Exploit, a strategy that initially draws comparable samples from all zones and then devotes all remaining rounds of play to HIV testing in whichever zone produced the highest observed yield; 3) Retrospection, a strategy using only base prevalence information; and; 4) Clairvoyance, a benchmarking strategy that employs perfect information about HIV prevalence in each zone.

RESULTS

Over 250 tournament runs, Thompson Sampling outperformed Explore-then-Exploit 66% of the time, identifying 15% more cases. Thompson Sampling's superiority persisted in a variety of circumstances examined in the sensitivity analysis. Case detection rates using Thompson Sampling were, on average, within 90% of the benchmark established by Clairvoyance. Retrospection was consistently the poorest performer.

LIMITATIONS

We did not consider either selection bias (i.e., the correlation between infection status and the decision to obtain an HIV test) or the costs of relocation to another zone from one round of play to the next.

CONCLUSIONS

Adaptive methods like Thompson Sampling for mobile HIV testing are practical and effective, and may have advantages over other commonly used strategies.

The landscape of inappropriate laboratory testing: a 15-year meta-analysis

BACKGROUND

Laboratory testing is the single highest-volume medical activity and drives clinical decision-making across medicine. However, the overall landscape of inappropriate testing, which is thought to be dominated by repeat testing, is unclear. Systematic differences in initial vs. repeat testing, measurement criteria, and other factors would suggest new priorities for improving laboratory testing.

METHODS

A multi-database systematic review was performed on published studies from 1997-2012 using strict inclusion and exclusion criteria. Over- vs. underutilization, initial vs. repeat testing, low- vs. high-volume testing, subjective vs. objective appropriateness criteria, and restrictive vs. permissive appropriateness criteria, among other factors, were assessed.

RESULTS

Overall mean rates of over- and underutilization were 20.6% (95% CI 16.2-24.9%) and 44.8% (95% CI 33.8-55.8%). Overutilization during initial testing (43.9%; 95% CI 35.4-52.5%) was six times higher than during repeat testing (7.4%; 95% CI 2.5-12.3%; P for stratum difference <0.001). Overutilization of low-volume tests (32.2%; 95% CI 25.0-39.4%) was three times that of high-volume tests (10.2%; 95% CI 2.6-17.7%; P<0.001). Overutilization measured according to restrictive criteria (44.2%; 95% CI 36.8-51.6%) was three times higher than for permissive criteria (12.0%; 95% CI 8.0-16.0%; P<0.001). Overutilization measured using subjective criteria (29.0%; 95% CI 21.9-36.1%) was nearly twice as high as for objective criteria (16.1%; 95% CI 11.0-21.2%; P = 0.004). Together, these factors explained over half (54%) of the overall variability in overutilization. There were no statistically significant differences between studies from the United States vs. elsewhere (P = 0.38) or among chemistry, hematology, microbiology, and molecular tests (P = 0.05-0.65) and no robust statistically significant trends over time.

CONCLUSIONS

The landscape of overutilization varies systematically by clinical setting (initial vs. repeat), test volume, and measurement criteria. Underutilization is also widespread, but understudied. Expanding the current focus on reducing repeat testing to include ordering the right test during initial evaluation may lead to fewer errors and better care.

Improving the efficiency of HIV testing with peer recruitment, financial incentives, and the involvement of persons living with HIV infection

BACKGROUND

The authors piloted an HIV testing and counseling (HTC) approach using respondent-driven sampling (RDS), financial incentives, and persons living with HIV infection (PLHIV).

METHODS

Eligible participants were aged 30-60 years, African American or black, and residents of Oakland, CA. Participants were tested for HIV infection and asked to refer up to 3 others. The authors compared the efficiency of RDS to conventional outreach-based HTC with the number needed to screen (NNS). They evaluated the effect of 2 randomly allocated recruitment incentives on the enrollment of high-risk or HIV-positive network associates: a flat incentive ($20) for eligible recruits or a conditional incentive ($10-35) for eligible recruits in priority groups, such as first-time testers.

RESULTS

Forty-eight participants (10 PLHIV and 38 HIV negative) initiated recruitment chains resulting in 243 network associates. Nine (3.7%) participants tested HIV positive, of whom 7 (78%) were previously recognized. RDS was more efficient than conventional HTC at identifying any PLHIV (new or previously recognized; RDS: NNS = 27, 95% CI: 14 to 59; conventional: NNS = 154, 95% CI: 95 to 270). There was no difference between the 2 incentive groups in the likelihood of recruiting at least 1 high-risk HIV-negative or HIV-positive network associate (adjusted odds ratio = 0.89, 95% CI: 0.06 to 13.06) or in total number of high-risk HIV-negative or HIV-positive associates (adjusted odds ratio = 0.79, 95% CI: 0.23 to 2.71).

CONCLUSIONS

Social network HTC strategies may increase demand for HTC and efficiently identify PLHIV. The flat incentive was as successful as the conditional incentive for recruiting high-risk individuals. Unexpectedly, this method also reidentified PLHIV aware of their status.

Shifting the paradigm: using HIV surveillance data as a foundation for improving HIV care and preventing HIV infection

CONTEXT

Reducing HIV incidence in the United States and improving health outcomes for people living with HIV hinge on improving access to highly effective treatment and overcoming barriers to continuous treatment. Using laboratory tests routinely reported for HIV surveillance to monitor individuals' receipt of HIV care and contacting them to facilitate optimal care could help achieve these objectives. Historically, surveillance-based public health intervention with individuals for HIV control has been controversial because of concerns that risks to privacy and autonomy could outweigh benefits. But with the availability of lifesaving, transmission-interrupting treatment for HIV infection, some health departments have begun surveillance-based outreach to facilitate HIV medical care.

METHODS

Guided by ethics frameworks, we explored the ethical arguments for changing the uses of HIV surveillance data. To identify ethical, procedural, and strategic considerations, we reviewed the activities of health departments that are using HIV surveillance data to contact persons identified as needing assistance with initiating or returning to care.

FINDINGS

Although privacy concerns surrounding the uses of HIV surveillance data still exist, there are ethical concerns associated with not using HIV surveillance to maximize the benefits from HIV medical care and treatment. Early efforts to use surveillance data to facilitate optimal HIV medical care illustrate how the ethical burdens may vary depending on the local context and the specifics of implementation. Health departments laid the foundation for these activities by engaging stakeholders to gain their trust in sharing sensitive information; establishing or strengthening legal, policy and governance infrastructure; and developing communication and follow-up protocols that protect privacy.

CONCLUSIONS

We describe a shift toward using HIV surveillance to facilitate optimal HIV care. Health departments should review the considerations outlined before implementing new uses of HIV surveillance data, and they should commit to an ongoing review of activities with the objective of balancing beneficence, respect for persons, and justice.

Using HIV surveillance data to monitor missed opportunities for linkage and engagement in HIV medical care

Monitoring delayed entry to HIV medical care is needed because it signifies that opportunities to prevent HIV transmission and mitigate disease progression have been missed. A central question for population-level monitoring is whether to consider a person linked to care after receipt of one CD4 or VL test. Using HIV surveillance data, we explored two definitions for estimating the number of HIV-diagnosed persons not linked to HIV medical care. We used receipt of at least one CD4 or VL test (definition 1) and two or more CD4 or VL tests (definition 2) to define linkage to care within 12 months and within 42 months of HIV diagnosis. In five jurisdictions, persons diagnosed from 12/2006-12/2008 who had not died or moved away and who had zero, or less than two reported CD4 or VL tests by 7/31/2010 were considered not linked to care under definitions 1 and 2, respectively. Among 13,600 persons followed up for 19-42 months; 1,732 (13%) had no reported CD4 or VL tests; 2,332 persons (17%) had only one CD4 or VL test and 9,536 persons (70%) had two or more CD4 or VL tests. To summarize, after more than 19 months, 30% of persons diagnosed with HIV had less than two CD4 or VL tests; more than half of them were considered to have entered care if entering care is defined as having one CD4 or VL test. Defining linkage to care as a single CD4 or VL may overestimate entry into care, particularly for certain subgroups.

Repeat Western blot testing after receiving an HIV diagnosis and its association with engagement in care

OBJECTIVES

To examine the prevalence of and factors associated with potentially unnecessary repeat confirmatory testing after initial HIV diagnosis and the relationship of repeat testing to medical care engagement.

DESIGN

South Carolina HIV/AIDS surveillance data for 12,504 individuals who were newly diagnosed with HIV infection between January 1997 and December 2008 were used for this analysis. State law requires that all positive Western blot [WB] results be reported regardless of frequency.

METHODS

HIV-infected persons, diagnosed from 1997-2008 and followed through 2009, with repeat positive WB results were compared to those who did not have repeat positive WB results. We defined repeat positive testing as documentation of one or more positive WB obtained ≥90 days following initial WB confirmatory result. HIV care engagement for the period from 2007-2009 was assessed by documentation of CD4+ T-cell/viral load reports to the South Carolina HIV/AIDS surveillance system during each six-month period of a calendar year for those individuals diagnosed prior to the assessment period and still alive at the end. Relative risk [RR] with 95% confidence intervals [CI] and multivariable general linear models were used to assess if any covariates of interest were independently associated with repeat positive confirmatory testing.

RESULTS

A total of 4,237 [34%] of 12,504 HIV-infected individuals had results of repeat positive WB testing reported to the surveillance system during 1997-2008. Persons who had repeat positive WB testing were more likely than persons who did not have repeat WB testing to have progressed to AIDS >1 year following diagnosis [RR: 1.70; 95% CI: 1.61, 1.80] and to be consistently in care [RR: 1.35; 95% CI: 1.24, 1.47] or have sporadic care [RR: 1.80; 95% CI: 1.68, 1.94].

DISCUSSION

Having repeat positive WB tests may be a marker of engaging HIV care. However, given the limited resources available for care, it is important that healthcare reform policy and clinical recommendations promote improvements in communications about previous test results.

How Much Should We Pay for a New HIV Diagnosis? A Mathematical Model of HIV Screening in US Clinical Settings

Objective. To develop a model to assist clinical setting decision makers in determining how much they can spend on human immunodeficiency virus (HIV) screening and still be cost-effective. Design. The authors developed a simple mathematical model relating the program cost per new HIV diagnosis to the cost per HIV infection averted and the cost per quality-adjusted life year (QALY) saved by screening. They estimated outcomes based on behavioral changes associated with awareness of HIV infection and applied the model to US sexually transmitted disease clinics. Methods. The authors based the cost per new HIV diagnosis (2009 US dollars) on the costs of testing and the proportion of persons who tested positive. Infections averted were calculated from the reduction in annual transmission rates between persons aware and unaware of their infections. The authors defined program costs from the sexually transmitted disease clinic perspective and treatment costs and QALYs saved from the societal perspective. They undertook numerous sensitivity analyses to determine the robustness of the base case results. Results. In the base case, the cost per new HIV diagnosis was $2528, the cost per infection averted was $40,516, and the cost per QALY saved was less than zero, or cost-saving. Given the model inputs, the cost per new diagnosis could increase to $22,909 to reach the cost-saving threshold and to $63,053 for the cost-effectiveness threshold. All sensitivity analyses showed that the cost-effectiveness results were consistent for extensive variation in the values of model inputs. Conclusions. HIV screening in a clinical setting is cost-effective for a wide range of testing costs, variations in positivity rates, reductions in HIV transmissions, and variation in the receipt of test results.